/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package com.zjdt.epserver.filter;

import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.dusin.web.util.JsonUtil;

/**
 *
 * @author dusin
 */
@WebFilter(filterName = "QXFilter", urlPatterns = {"/*"})
public class QXFilter implements Filter {
    private final Set<String> noFilterUrl;
    
    private static final boolean debug = true;

    // The filter configuration object we are associated with.  If
    // this value is null, this filter instance is not currently
    // configured. 
    private FilterConfig filterConfig = null;
    
    public QXFilter() {
        this.noFilterUrl = new HashSet<String>();
        noFilterUrl.add("");
    }    
    
    private void doBeforeProcessing(ServletRequest request, ServletResponse response)
            throws IOException, ServletException {
        if (debug) {
            log("QXFilter:DoBeforeProcessing");
        }
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
        
        String url = (String) req.getRequestURI();
        String s = req.getContextPath();        
        String loginName = (String) req.getSession().getAttribute("username");
        if((url.startsWith("/EPServer/jsp/main")&&url.endsWith("jsp"))
                ||(url.startsWith("/EPServer/servlet/web"))){//需要判断是否登陆
            
            if(loginName==null||"".equals(loginName)){
                //res.sendRedirect(s + "/jsp/home/sessiontimeout.jsp");
                req.getRequestDispatcher( "/jsp/home/sessiontimeout.jsp").forward(req, res);
            }            
            //res.sendRedirect();
            //req.getRequestDispatcher( "/jsp/home/sessiontimeout.jsp").forward(req, res);
        }
        //判断是否有该页面的访问权限
        if(!url.endsWith("usermain.jsp")&&!"super".equals(loginName)&&url.startsWith("/EPServer/jsp/main")&&url.endsWith("jsp")){
            if(!hasUrl(req.getSession(),url)){
                req.getRequestDispatcher( "/jsp/home/noright.jsp").forward(req, res);
            }
        }
    }    
    
    //检查session中是否有该链接
    private boolean hasUrl(HttpSession session,String url){
        List<Map<String,Object>> modules = (List<Map<String,Object>>) session.getAttribute("modules");
        for(Map<String,Object> m:modules){
            String urlAvailable = (String)m.get("url");
            if(url.endsWith(urlAvailable)){
                return true;
            }
        }
        return false;
    }
    
    private void doAfterProcessing(ServletRequest request, ServletResponse response)
            throws IOException, ServletException {
        if (debug) {
            log("QXFilter:DoAfterProcessing");
        }

	// Write code here to process the request and/or response after
        // the rest of the filter chain is invoked.
	// For example, a logging filter might log the attributes on the
        // request object after the request has been processed. 
	/*
         for (Enumeration en = request.getAttributeNames(); en.hasMoreElements(); ) {
         String name = (String)en.nextElement();
         Object value = request.getAttribute(name);
         log("attribute: " + name + "=" + value.toString());

         }
         */
	// For example, a filter might append something to the response.
	/*
         PrintWriter respOut = new PrintWriter(response.getWriter());
         respOut.println("<P><B>This has been appended by an intrusive filter.</B>");
         */
    }

    /**
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException {
        
        if (debug) {
            log("QXFilter:doFilter()");
        }
        
        doBeforeProcessing(request, response);
        
        Throwable problem = null;
        try {
            chain.doFilter(request, response);
        } catch (Throwable t) {
	    // If an exception is thrown somewhere down the filter chain,
            // we still want to execute our after processing, and then
            // rethrow the problem after that.
            problem = t;
            t.printStackTrace();
        }
        
        doAfterProcessing(request, response);

	// If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        if (problem != null) {
            if (problem instanceof ServletException) {
                throw (ServletException) problem;
            }
            if (problem instanceof IOException) {
                throw (IOException) problem;
            }
            sendProcessingError(problem, response);
        }
    }

    /**
     * Return the filter configuration object for this filter.
     */
    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
    }

    /**
     * Set the filter configuration object for this filter.
     *
     * @param filterConfig The filter configuration object
     */
    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }

    /**
     * Destroy method for this filter
     */
    public void destroy() {        
    }

    /**
     * Init method for this filter
     */
    public void init(FilterConfig filterConfig) {        
        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            if (debug) {                
                log("QXFilter:Initializing filter");
            }
        }
    }

    /**
     * Return a String representation of this object.
     */
    @Override
    public String toString() {
        if (filterConfig == null) {
            return ("QXFilter()");
        }
        StringBuffer sb = new StringBuffer("QXFilter(");
        sb.append(filterConfig);
        sb.append(")");
        return (sb.toString());
    }
    
    private void sendProcessingError(Throwable t, ServletResponse response) {
        String stackTrace = getStackTrace(t);        
        
        if (stackTrace != null && !stackTrace.equals("")) {
            try {
                response.setContentType("text/html");
                PrintStream ps = new PrintStream(response.getOutputStream());
                PrintWriter pw = new PrintWriter(ps);                
                pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N

                // PENDING! Localize this for next official release
                pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");                
                pw.print(stackTrace);                
                pw.print("</pre></body>\n</html>"); //NOI18N
                pw.close();
                ps.close();
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        } else {
            try {
                PrintStream ps = new PrintStream(response.getOutputStream());
                t.printStackTrace(ps);
                ps.close();
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        }
    }
    
    public static String getStackTrace(Throwable t) {
        String stackTrace = null;
        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch (Exception ex) {
        }
        return stackTrace;
    }
    
    public void log(String msg) {
        filterConfig.getServletContext().log(msg);        
    }
    
}
